Telecommunication systems are operable to connect two or more telecommunications ports through a variety of data transmission media. For example, a first telecommunications port may be coupled to a microwave data transmission medium, which may in turn be coupled to a copper conductor data transmission medium, then to a fiber optic data transmission medium, and subsequently to a second telecommunications port. In this example, telecommunications data is transmitted through a telecommunications channel between the first telecommunications port and the second telecommunications port via the microwave data transmission medium, the copper conductor data transmission medium, and the fiber optic data transmission medium.
Modern telecommunication systems are typically comprised of a large number of telecommunications ports connected to a large number of data transmission media. These media may utilize large signal frequency bandwidths, such that two or more telecommunications channels may be combined for transmission over the data transmission media by multiplexing. In order to connect any given port to any other given port, it is necessary to utilize specialized telecommunication switches, which are used to connect the data transmission media. Such telecommunication switches are capable of connecting any of a large number (M) of input ports to any of a large number (N) of output ports, with a different data transmission medium connected to each input and output port. Furthermore, these switches may be capable of demultiplexing the signal carried over a given media in order to provide switching capability for multiplexed telecommunications channels.
A digital cross-connect system is a specialized telecommunications switch that provides improved flexibility in switching services. An example of a modern digital cross-connect system is provided by U.S. Pat. No. 5,436,890 to Read et al entitled “Integrated Multi-rate Cross-Connect System,” assigned to DSC Communications Corporation, issued Jul. 25, 1995 (hereinafter “Read”). In addition to a telecommunications switch operable to connect any of M input ports to any of N output ports, the digital cross-connect system taught in Read contains redundant parallel planes of all components, such that the digital cross-connect system can experience a number of failures in the components that comprise both planes without loss of network traffic.
Despite the additional flexibility inherent in digital cross-connect systems, connection of data transmission media to the digital cross-connect system input ports and output ports must be coordinated in order to optimize telecommunications traffic flow. For example, it may be desirable to transmit telecommunications traffic from an input port of a first digital cross-connect system to an output port of a second digital cross-connect system. While this connection may be accomplished by providing connections between an output port of the first digital cross-connect system and an input port of the second digital cross-connect system, such connections consume digital cross-connect system resources, i.e., input ports and output ports.
Furthermore, if two or more separate and discrete digital cross-connect systems are being used to route telecommunications traffic, a significant amount of digital cross-connect system resources must be used to interconnect the digital cross-connect systems. In many cases, it is desirable to use two or more physically separated digital cross connects, such as when a small number of telephony circuits are connected to network interfaces, but to later increase the number of digital cross connects and, subsequently, the number of connections between digital cross connects, such as when the number of telephony circuits connected to network interfaces has increased. Presently available digital cross connect systems do not readily accommodate such increases in the number of network interfaces, and require network interfaces to be remapped in order to decrease the number of connections which must be made between digital cross connect systems.